Valving associated with variable capacity pump



April 3, 1956 J. J. O'MALLEY VALVING ASSOCIATED WITH VARIABLE CAPACITYPUMP FJ'led Deo. 27, 1954 I l l IK ATTORNEY United States Patent VALVINGASSOCIATED WITH VARIABLE CAPACITY PUMP John J. OMalley, Detroit,lVIich., assigner to General Motors Corporation, Detroit, Mich., acorporation of Delaware Application December 27, 1954, Serial No.477,856

7 Claims. (Cl. 60-52) This invention relates to valving associated witha variable capacity uid pump to control the amount of oil to be cooledin accordance with the pumping capacity of the pump.

ln motor vehicles equipped with automatic transmissions having uidpressure operated power devices, uid couplings, torque converters or thelike, the temperature of the oil used to operate these devices tends attimes to become dangerously high. Therefore, an oil cooling means issometimes provided for cooling the oil as it is recirculated by the pumpafter its return to the transmission sump.

Therefore, it is an object of this invention to provide a valveassociated with a variable Capacity pump to .admit oil from the pump toa cooling means whenever the pumping capacity of the iluid pump is belowits maximum.

It is a further object to provide a cooling system wherein oil issupplied to a fluid operating means through a cooling means in such amanner that in the event that the cooling means becomes congested orunworkable, oil from a variable capacity pump can ilow directly to theuid operating means through a safety valve in a conduit by-passingthe-cooling means.

ln the general operation of this device, a variable capacity pump isprovided with a guide ring slidably mounted so as to be variablypositioned eccentrically or concentrically of the driving means-of thepump for maximum and minimum pumping capacities, respectively. This pumpsupplies lluid by one conduit to a pressure regulator valve, theposition of which controls the output capacity of the pump bycontrolling the admission of oil to act on opposite portions of theguide ring. By means of a branch conduit, output from the pump issupplied to a second valve adapted to be actuated by the guide ring ofthe pump to admit oil to a uid pressure operating device through acooling means, or lthrough a by-pass conduit if the cooling means isblocked.

Other objects, features and advantages of the invention will becomeapparent by reference to the following detailed description of theaccompanying figure wherein is shown a diagrammatic arrangement ot thevalving associated with a variable capacity fluid pump.

Referring to the drawing, P indicates a variable capacity uid pump for atransmission oil system having a core 11 adapted to be connected to asuitable drive member 12 which can be either a rotating part of thedrive or driven shaft of a transmission. This pump is ot` a type wellknown in the art and of which an example is shown and described indetail in the co-pending application of Walter B. Herndon et al.,entitled, Variable Capacity Pump, S. N. 450,908, tiled August 19, 1954.The pump P has a casing 13, a capacity-varying guide ring 14 adapted tobe variably positioned radially within the casing, a guide vane ring 15mounting pumping vanes 16 slidably within core member 12, a uid Vsuctioninlet conduit 17, and a uid discharge conduit 18. A hollowed out space19 is provided for moving the guide position.

ring 14 radially outwardly by uid pressure to increase the pumpingcapacity of the pump due to the eccentric position of the guide ringwith respect to the core. Corresponding spaces 20 are provided oppositespace 19 for moving the guide ring inwardly by fluid pressure todecrease the pumping capacity. A spring 21 positioned between the casingand the guide ring normally biases guide ring 14 to a radially outermost,position corresponding to maximum pumping capacity.

The main pump outlet conduit 18 has a branch conduit 22 leading to aplurality of valves.23 andf24. Valve 23 is a pressure regulating valvehaving a central bore 25 communicating selectively with conduits 26 and27 by means of an opening 128 lbetween the lbalanced areas of lands 29and 30. Conduits 26 and 27 connect with spaces 19 and 20, respectively,to vary the position of guide ring 14. Movement of valve 23 in onedirection is controlled by fluid pressure from conduit 18 acting on face31 of one end of the valve 23. Positioned between a shoulder-33 of valve23 and a plug member 34 slidable within a stop member 35 secured tothevalve body, .is a spring 32 which opposes the action of `liuid pressureacting on face 3l and tends to restrain movement of the valve. 37 and 38are exhaust ports connected to the sump (not shown).

In its initial position, the valve y23 is in the position shownconnecting lluid pressure from conduit 18 to ,space 19 by way of bore'25 and conduit 26, aiding spring 721 to keep guide ring 14 in itsmaximum pumping capacity As uid pressure increases, the valve moves toconnect conduit 26 to .exhaust port 37 and conduit 27 to .the fluidpressure supply to move the guide ring to decrease the pumping capacity,thereby regulating the output pressure.

When it is desired to increase pump pressure 4above the substantiallyconstant pressure level ,provided by the normal action of the pressureregulator valve, a conduit 36 is adapted to supply fluid pressure yfromthe output of the pump to act on plug 34 to increase the spring forceacting on shoulder 33, thereby inserting an additional force opposingmovement of valve 23 to connect bore 2S and conduit 27. The supply offluid to conduit 36 may be controlled by any well-known manuallyoperated valve means '(no't shown).

In addition to the flow to valve 23, fluid pressure `from line 22 isalso supplied to -a cooling means, designated by block 49, andyfluidpressure operating means designated by block 50 through a valve24. This valve is slidably positioned within casing member 13 with oneend 39 abutting the guide ring 14 for movement therewith in bothdirections. The end 39 is positioned Within space 20 so as .to besubject to 'fluid pressure when oil is admitted 'to conduit 27. A spring40 is Vpositioned between the other end of valve 24 and a stop sealmember 41 secured to the casing. A central bore 42 is provided to permitcommunication between opposite ends of the valve. The opposite ends ofthe valve are provided with faces whose areas are equal, therebyestablishing a balance of iluid pressure forces acting in oppositedirections on the valve,ppermitting spring 40 to bias valve y24 againstring guide 14 for movement therewith. A reduced portion 43 of the valveis provided to permit the oil to tlow from line 22 to Ya line 44 whentheguide ring 14 moves inwardly from 'theposition shown. Line .22 suppliesoil to a passage 45 through a safety ball-check valve .unit '46 and to apassage 47 leading to the cooling means 49. Line 45 connects with thefluid pressure operating means. Line 48 is a return conduit from thecooling means and is connected with line 4S. The safety valve unitoperates in such a mannerthat oil from line 22 forces the ball 'oli itsvseat against'the spring pressure to supply oil directly `to the line 45inthe event that the cooler becomes clogged or congested preventing oilin line 47 from reaching the pressure operating means Sil. This Valvewill also open when the oil is cold on entering the cooler, such as on acold start of a vehicle, because the stillness of the oil will preventit from passing through the cooler quickly thereby building up the oilpressure to unseat the valve. Line 22 also supplies oil to the coolerthrough line 47. The ball-check valve will remain open until thestiiness or congestion due to dirt, etc. is relieved, thereby permittingthe spring to seat the ball and cause all or the fluid in line 45 to besupplied from line 22 by way of the cooling means.

Referring more in detail to the actual operation of this device; withthe pump at rest, spring 21 biases guide ring 14 to its outermost radialposition which corresponds to the maximum pumping capacity. The pressureregulator valve 23, in its initial position, permits communicationbetween lines 22 and space 19 through bore 25, Valve 24, in its initialposition, is in the position shown in the gure, i. e., in a closedposition preventing communication of oil from line 22 to line 44. Inthis position, valve 24 is held in contact with guide ring 14 by meansof spring 40. As soon as rotation is imparted to shaft 12, valve 23 issupplied with fluid from pump output lines 1S and 22 to communicate withspace 19 by means of bore 25 and conduit 26 to assist spring 21 inholding the guide ring in its maximum pumping capacity position. As soonas sucient fluid pressure is built up behind the face 31 of valve 23,the valve will move against opposition by spring 32 to connect space 19with exhaust passage 37 and connect the oil to spaces 20 by means ofconduit 27, thereby tending to move guide ring 14 against the spring 21to decrease the pumping capacity. As soon as oil is admitted to space2G, it flows through the bore l2 of valve 24 to act on opposite ends ofthe valve. Since the total areas of opposite ends of the valves are thesame, the iluid pressure forces will be balanced thereby permittingspring 40 to keep the valve 24 in abutting relationship with guide ring14. As soon as guide ring 14 moves radially inwardly, valve 24 will moveto an open psition permitting communication between lines 22 and 4 Oilpressure admitted through valve 24 acts on the safety valve 46 and isalso routed through line 47 to the cooling means 49 to return throughline 48 to act on the pressure operating means Sil and to the oppositeside of the safety valve unit 46. Since the oil pressure on oppositesides of the ball of the safety check valve are balanced, the springwill seat the ball, thereby assuring that all the oil supplied to line4S will pass through the cooling means, as long as valve 24 remains inan open position. As valve 24 opens and closes intermittently, thesupply of fluid to line will be alternately by way of tbe ball-checkvalve or through the cooling means.

The determination of whether valve 24 will be in an open or closedposition will depend upon the action of the pressure regulator valve 23.As valve 23 is moved by duid pressure to decrease the pumping capacityof the pump, spring 32 tends to increase the capacity. Therefore, thevalve will tend to seek a constant pressure level. Fluid may be admittedto line 36 to act on plug 34 to vary the opposition of spring 32 toincrease the fluid pressure level above its normal range since thepressure inline 36 will tend to open communication between lines 22 andspace 19 to increase the pumping capacity.

From the foregoing it will be seen that the present invention provides areliable and eicient manner of cooling the oil being delivered to atransmission operating mechanism in accordance with variations in thepumping capacity of a variable capacity pump. The inventionassures thatunder normal pumping conditions, the oil will be circulated through thecooler substantially at all times eliminating the danger of injury tothe transmission. lt will be understood that the invention can bemodified beyond the illustrated embodiment, and therefore anylimitations to be imposed are those set forth in the following claims.

l claim:

1. ln a cooling system, a variable capacity pump for providing a sourceof lluid pressure, said pump having movable slide means for varying thepumping capacity of said pump from a maximum to a minimum, means forcausing movement of said capacity varying means, a valve associated withsaid capacity varying means, said valve having an open and a normallyclosed'position, a cooling means, conduit means connecting said coolingmeans and said source, said valve being positioned within said conduitbetween said source and said cooling means, and biasing means foropening said valve to permit communication between said source andcooling means when said capacity varying means is moved from a maximumpumping capacity position.

2. ln a. cooling system, a variable capacity pump providing a source offluid pressure and having a casing, a slide within said casing forvarying the pumping capacity of said pump by movement between a maximumand other pumping capacity positions, fluid pressure means 'for movingsaid slide, a valve means associated with said slide, biasing meansacting on said valve to bias said valve for a movement proportional tothe movement of said slide when said slide is moved, a cooling means forcooling said uid, conduit means connecting said source of tluidpressure, said valve and said cooling means, said valve means permittingcommunication between said source and said cooling means when said slidemeans is moved from its maximum pumping capacity position.

3. In a fluid system, a variable capacity pump providing a source othuid pressure, said pump including a slide member movable to vary theoutput pressure of said pump, means for moving said slide member, valvemeans in abutting relationship with said slide member and adapted formovement therewith, said valve means having open and closed positions, ailuid pressure operating mechanism, conduit means connecting said sourceand said mechanism through said valve means, said slide having aninitial position permitting said valve means to close, said valvemechanism permitting communication between said mechanism and saidsource when said slide is moved from its initial position.

4. A cooling system including a variable capacity pump providing asource of fluid pressure, a slide member within said pump for varyingthe capacity thereof, said slide member having maximum and other pumpingcapacity positions, means for moving'said slide comprising iluidpressure means connected to said source, a cooling means for said uid,conduit means connecting said source and said cooling means, valve meanshaving open and closed positions controlling corrununication of saidsource with said cooling means, said valve means being positioned inabutting relationship at one end with said slide member, spring meansbiasing the other end of said valve means against said slide member,pressure regulating means controlling the slide moving means, said valvemeans being in communication at the one end with said uid pressure meanswhen said pressure regulating means permits, a bore in said valveconnecting opposite ends of said valve to said uid pressure means so asto cause a balance of pressures at both ends of said valve permittingsaid spring to maintain said valve against said slide means, wherebysaid valve means opens permitting duid to ilow from said source to saidcooling means when said slide member is moved from its maximum position.l,

5 In a cooling system, a variable capacity pump providing a source ofiluid pressure, a casing for said pump, a slide within said casingmovable to vary the capacity of said pump, a cooling means for saidiluid, conduit means connecting said source and saidcooling means, saidcasing having a valve means therein adapted to be actuated in onedirection by said slide, said valve having open and closed positionscontrolling communication between said source and said cooling means, aspring biasing said valve for movement in another direction, and conduitmeans connecting said source and said slide for moving said slide by uidpressure, whereby when said slide is moved said valve will be actuatedto control admission of uid from said source to the cooling means.

6. In a cooling system, a variable capacity pump providing a source ofuid pressure, a uid pressure operating device, conduit means connectingsaid source and said device, a casing for said pump, a pump varyingcapacity slide within said casing, means for moving said slide, a valvemeans in said casing having open and closed positions and adapted to bemoved by said slide, said valve means controlling communication betweensaid source and said device, a cooling means in said conduit betweensaid valve means and said device, other conduit means connecting saidvalve and said device by-passing said cooling means, and valve means insaid by-pass adapted to be actuated by uid pressure from said sourcewhen said slide moves to open said rst mentioned valve means to permituid pressure to be applied directly to said device by passing saidcooling means prior to uid being applied to said device through saidcooling means.

7. In a cooling system, a variable capacity pump providing a source ofiiuid pressure, slide means movably positioned within said pump to varythe pumping capacity thereof, said slide means having maximum and otherpumping capacity positions, uid pressure operated means for controllingmovement of said slide means to thereby vary said pump capacity, acooling means for cooling said fluid, uid conduit means between saidsource and said cooling means, and valve means positioned within saidconduit for controlling the admission of fluid from said source to saidcooling means, said valve means being positioned adjacent said slidemeans for movement therewith to permit uid to pass from said Asource tosaid cooling means whenever said slide means is in its other positions.

References Cited in the le of this patent UNITED STATES PATENTS2,166,423 Clark July 18, 1939 2,228,364 Philipp Jan. 14, 1941 2,520,674Buschmann Aug. 29, 1950 2,600,632 French June 17, 1952 2,645,899 Alleret al July 21, 1953

